You could do what I do. I use a shroud I modified to fit and a flex fan which cools fine with my aluminum rad as it runs about 185 to 190 in average hot days. But if I get stuck in traffic and have to sit and idle to long on very hot days it will creep up to 205 so I figured I would add an electric fan for backup on a toggle switch I can turn on in traffic and see how it works. And it works great for me as even when I had to sit in traffic for 45 minutes on a 90+ degree day it kept it from going over 200 as it got up to about 200 and never went higher. It is a nice feeling having that backup for when I get stuck in traffic. A clutch fan is also nice and may pull more air at idle but I dont really have the room for the factory clutch fan and this setup seems to do the trick on my 63 with my 440 based 493. Ron